High efficiency LED lighting

Abstract

An LED lighting system may include one or more light-emitting diodes and one or more power management modules. Components of the LED lighting system may be selected and arranged, for example, to match a load voltage to an operating voltage. Matching the load voltage to the operating voltage may enable efficient use of power by the LED lighting system. A method of selecting components of the LED lighting system is provided. For example, the components may be selected based on a target luminance and a given operating voltage. The method may be facilitated and/or implemented with a computer.

What is claimed is: 
     
       1. An LED lighting system, comprising:
 a set of light-emitting diodes; 
 a first circuit module configured at least to maintain an operating voltage; and 
 a second circuit module comprising a set of transistors and a set of resistors, the second circuit module configured to, at least, provide power to the set of light-emitting diodes, regulate a current flowing through the set of light-emitting diodes and match a load voltage across at least the set of light-emitting diodes, at least one of the set of transistors and at least one of the set of resistors to the operating voltage, wherein the load voltage matches the operating voltage if an absolute difference between the load voltage and the operating voltage is less than a threshold. 
 
     
     
       2. The system of  claim 1 , wherein the set of light-emitting diodes comprises a plurality of light-emitting diodes having at least one matching attribute. 
     
     
       3. An LED lighting system, comprising:
 a set of light-emitting diodes; 
 a first circuit module configured at least to maintain an operating voltage; and 
 a second circuit module comprising a set of transistors and a set of resistors including a plurality of resistors connected in parallel, the second circuit module configured to, at least, provide power to the set of light-emitting diodes, regulate a current flowing through the set of light-emitting diodes and match a load voltage across at least the set of light-emitting diodes, at least one of the set of transistors and at least one of the set of resistors to the operating voltage. 
 
     
     
       4. The system of  claim 1 , wherein the set of transistors comprises:
 a first transistor that is a field effect transistor; and 
 a second transistor connected at least to a gate of the first transistor. 
 
     
     
       5. The system of  claim 4 , wherein the current flowing through the set of light-emitting diodes is regulated with at least the first transistor and the second transistor. 
     
     
       6. An LED lighting system, comprising:
 a set of light-emitting diodes; 
 a first circuit module configured at least to maintain an operating voltage; and 
 a second circuit module comprising a set of transistors and a set of resistors, the second circuit module configured to, at least, provide power to the set of light-emitting diodes, regulate a current flowing through the set of light-emitting diodes and match a load voltage across at least the set of light-emitting diodes, at least one of the set of transistors and at least one of the set of resistors to the operating voltage, 
 wherein the set of transistors comprises a first transistor that is a field effect transistor and a second transistor connected at least to a gate of the first transistor, the current flowing through the set of light-emitting diodes is regulated with at least the first transistor and the second transistor, and regulating the current flowing through the set of light-emitting diodes comprises maintaining the current flow less than or substantially equal to a threshold value. 
 
     
     
       7. An LED lighting system, comprising:
 a set of light-emitting diodes; 
 a first circuit module configured at least to maintain an operating voltage; and 
 a second circuit module comprising a set of transistors and a set of resistors, the second circuit module configured to, at least, provide power to the set of light-emitting diodes, regulate a current flowing through the set of light-emitting diodes and match a load voltage across at least the set of light-emitting diodes, at least one of the set of transistors and at least one of the set of resistors to the operating voltage, wherein the second circuit module further comprises a phototransistor and a resistor for daylight harvesting. 
 
     
     
       8. The system of  claim 7 , wherein:
 the phototransistor and the resistor for daylight harvesting are connected in series; and 
 the resistor for daylight harvesting is connected to at least one of the set of transistors. 
 
     
     
       9. The system of  claim 7 , wherein a value of the resistor for daylight harvesting corresponds to an amount of dimming of the set of light-emitting diodes in response to light received at the phototransistor. 
     
     
       10. The system of  claim 1 , wherein the LED lighting system is a dimmable LED lighting system. 
     
     
       11. An LED lighting system, comprising:
 a set of light-emitting diodes; 
 a first circuit module configured at least to maintain an operating voltage; 
 a second circuit module comprising a set of transistors and a set of resistors, the second circuit module configured to, at least, provide power to the set of light-emitting diodes, regulate a current flowing through the set of light-emitting diodes and match a load voltage across at least the set of light-emitting diodes, at least one of the set of transistors and at least one of the set of resistors to the operating voltage; and 
 a dimmer load, 
 wherein the LED lighting system is a dimmable LED lighting system. 
 
     
     
       12. An LED lighting system, comprising:
 a plurality of sets of light-emitting diodes; 
 a first circuit module configured at least to maintain an operating voltage; 
 for each of the plurality of sets of light-emitting diodes, a second circuit module comprising a set of transistors and a set of resistors, the second circuit module configured to, at least, provide power to the set of light-emitting diodes, regulate a current flowing through the set of light-emitting diodes and match a load voltage across at least the set of light-emitting diodes, at least one of the set of transistors and at least one of the set of resistors to the operating voltage; and 
 a lifetime optimization module configured at least to select which of the plurality of sets are powered during a time period. 
 
     
     
       13. The system of  claim 12 , wherein the ones of the plurality of sets that are powered during the time period are selected pseudorandomly. 
     
     
       14. The system of  claim 12 , wherein the proportion of the plurality of sets that are powered during the time period is determined based at least in part on an operating age of light-emitting diodes in the sets of the plurality. 
     
     
       15. An LED lighting system, comprising:
 a set of light-emitting diodes; 
 a first circuit module configured at least to maintain an operating voltage; 
 a second circuit module comprising a set of transistors, a set of resistors and a positive temperature coefficient thermistor, the second circuit module configured to, at least:
 provide power to the set of light-emitting diodes, regulate a current flowing through the set of light-emitting diodes and match a load voltage across at least the set of light-emitting diodes, at least one of the set of transistors and at least one of the set of resistors to the operating voltage; and 
 regulate a temperature of the set of light-emitting diodes based at least in part on a temperature of the positive temperature coefficient thermistor. 
 
 
     
     
       16. A method of effecting an LED lighting system, comprising:
 determining an operating current based on, at least, a target luminance and an operating voltage; 
 selecting a set of light-emitting diodes based on, at least, the operating current; 
 selecting a set of resistors in a circuit module that provides power to the set of light-emitting diodes, the selection of the set of resistors based at least in part on a goal of matching a load voltage across at least the set of light-emitting diodes, a set of transistors and the set of resistors to the operating voltage; and 
 selecting a positive temperature coefficient thermistor in the circuit module based at least in part on a goal of maintaining a temperature of the set of light-emitting diodes below a threshold value. 
 
     
     
       17. The method of  claim 16 , wherein selecting the set of light-emitting diodes comprises selecting a type of light-emitting diode having a nominal operating current near to the determined operating current. 
     
     
       18. The method of  claim 16 , wherein:
 each light-emitting diode in the set has an associated voltage drop when operated at the operating current; and 
 selecting the set of light-emitting diodes comprises selecting the set of light-emitting diodes at least so that a sum of the associated voltage drops is less than or substantially equal to the operating voltage. 
 
     
     
       19. The method of  claim 16 , wherein the operating voltage comprises a rectified voltage. 
     
     
       20. The method of  claim 16 , wherein the selection of the set of resistors is based at least in part on a goal of matching a load voltage across at least the set of light-emitting diodes, the set of transistors, the positive temperature coefficient thermistor and the set of resistors to the operating voltage. 
     
     
       21. At least one non-transitory computer-readable medium collectively having thereon computer-executable instructions to facilitate, at least:
 determining an operating current based on, at least, a target luminance and an operating voltage; 
 selecting a set of light-emitting diodes based on, at least, the operating current; 
 selecting a set of resistors for a circuit module for providing power to the set of light-emitting diodes, the selection of the set of resistors based at least in part on a goal of matching a voltage across at least the set of light-emitting diodes, a set of transistors and the set of resistors to the operating voltage; and 
 selecting a positive temperature coefficient thermistor in the circuit module based at least in part on a goal of maintaining a temperature of the set of light-emitting diodes below a threshold value. 
 
     
     
       22. An LED lighting system, comprising:
 a set of light-emitting diodes; 
 a first circuit module configured at least to maintain an operating voltage; and 
 a second circuit module comprising a set of transistors and a positive temperature coefficient thermistor, the second circuit module configured to, at least:
 provide power to the set of light-emitting diodes and regulate a temperature of the set of light-emitting diodes based at least in part on a temperature of the positive temperature coefficient thermistor; and 
 match a load voltage across at least the set of light-emitting diodes, at least one of the set of transistors and the positive temperature coefficient thermistor to the operating voltage.